Do I need to lift my car up before adjusting lug nut torque?

Question

I recently put new wheels on my car. I don't have off-street parking, much less a garage to work in, so I had the wheels installed by a mechanic. Since they were installed, they have been driven through about 100 miles, including an autocross event, so I think it's about time to check the lug nut torque.

I refuse to take it to a mechanic just for this, so I'll do it myself. I've got a torque wrench and appropriate sockets, but I'm not sure whether the weight of the car affects the torque I'd see on the lugs. Do I need to lift the car up to take the weight off the wheels while I check the torque?

Answer 1

Nope, doing it with the wheels on the ground if fine, no need to lift the weight of the wheels. It's easier that way because the wheels can't turn while you are torquing the lugs.

Answer 2

It's already well answered here but typically you torque items "under load". Since torque values specify a clamping force you want to be sure that the conditions of the part are most like the "real world" when you set the torque. When I do tires I center the tire and snug down all lugs before putting load back on the suspension and then torquing the lugs.

This is most especially important when working with upper and lower control arms. You want the weight on the tires and the suspension settled before torquing those down. Otherwise you may bind it all together at an awkward angle and put unneeded stress on your bushings.

Answer 3

Wrong. Do a test. Torque one wheel unloaded and one wheel loaded. Then with both wheels unloaded, loosen them. They are not the same.